1. Field of the Invention
The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly, to a method for manufacturing a fringe field switching mode liquid crystal display device.
2. Discussion of the Related Art
In order to improve a low aperture ratio and a low transmittance of a common IPS mode liquid crystal display device, a fringe field switching mode liquid crystal display device, which is a liquid crystal display device having a high aperture ratio and a high transmittance, has been devised.
FIG. 1 is a sectional view schematically illustrating a lower substrate of a conventional fringe field switching mode liquid crystal display device.
A lower substrate of a conventional fringe field switching mode liquid crystal display device, as shown in FIG. 1, includes a thin film transistor (TFT, not shown) having a gate electrode, a semiconductor layer, a source electrode and a drain electrode, which are formed on an insulating substrate 1, a transparent pixel electrode 3 connected to the drain electrode (not shown) of the TFT, a passivation film 5 formed on the TFT and the pixel electrode 3, and a transparent common electrode 7 formed on the passivation film 5 so as to be overlapped with the pixel electrode 3.
An upper substrate (not shown) is mounted at a predetermined gap from the lower substrate 1 while opposing the lower substrate 1. A liquid crystal layer (not shown) is interposed between the upper substrate (not shown) and the lower substrate 1. Because a so-called cell gap, which is a gap between the lower substrate 1 and the upper substrate (not shown), is formed to be larger than a gap between the common electrode 7 and the pixel electrode 3, a fringe field of a parabolic shape is formed between the common electrode 7 and the pixel electrode 3.
However, when the above-described conventional fringe field switching mode liquid crystal display device is manufactured, six mask processes for forming the TFT (which includes a mask process for forming the gate electrode, a mask process for forming the semiconductor layer, a mask process for forming the source/drain electrodes, a mask process for patterning the passivation film, a mask process for forming the common electrode, and a mask process for forming the pixel electrode) should be performed. In this regard, a new method for manufacturing a fringe field switching mode liquid crystal display device, which can reduce mask processes, is being required to be developed.